Real Estate
Office Property Cash Flow Calculator
Underwrite occupied office area, contractual rent, recoveries, vacancy, operating costs, reserves, debt service, and the occupancy floor needed to protect cash flow.
Lease economics
Measure office income after vacancy, recoveries, ownership costs, reserves, and debt
Use annualized lease assumptions from the current rent roll; do not substitute asking rent for signed rent.Income protection view
Occupied-area income bridge and debt-service gate
The orange marker is the occupancy needed for cash flow after reserves to reach zero.Detailed calculation process
Contract rent becomes cash flow only after every property-level claim is recognized
General symbolic formulas
O = Ao / AEGI = Ao(R + C) + INOI = EGI - AECF = NOI - AQ - DDSCR = NOI / DO0 = (AE + AQ + D - I) / [A(R + C)]Occupied square feet earn base rent and recoveries. Building operating expense and reserve are charged across total rentable area; debt service is then deducted. The zero-cash-flow occupancy formula reverses that sequence.
What each symbol means
A rentable area (ft²)Ao occupied area (ft²)R base rent ($/ft²/year)C recovery ($/occupied ft²/year)I other income ($/year)E operating expense ($/ft²/year)Q reserve ($/ft²/year)D debt service ($/year)
Worked substitution with current inputs
Annual office cash-flow ledger
| Line | Calculation basis | Annual amount |
|---|
How to use the result
- Enter rentable and currently occupied area from the rent roll.
- Use contractual annual rent and reimbursable expenses.
- Compare DSCR and occupancy floor with lender covenants and rollover risk.
Practical examples
Lease-up: test 31,500 ft² occupied to see whether debt remains covered before a new tenant starts.
Renewal: compare a lower renewal rent with the downtime and tenant-improvement cost avoided.
Useful underwriting checks
- Reconcile occupied area to executed commencement dates.
- Separate recoverable from nonrecoverable expenses.
- Budget leasing commissions and tenant improvements outside recurring NOI.
Limitations
This annual snapshot does not model lease expirations, free-rent periods, step rents, reimbursements by tenant, capital projects, sale costs, taxes, or monthly financing draws.
Office property cash-flow FAQ
Is reserve included in NOI?
No. NOI is shown before reserve; cash flow deducts reserve and debt service separately.
Why charge operating expense on vacant space?
Many building costs continue across the whole property even when a suite is vacant.
Is the occupancy floor a leasing target?
It is a mathematical cash-flow floor under the entered rents and costs, not a substitute for tenant-credit or rollover analysis.